YORK, Pa. - Stevenson baseball junior Alec Romanowski allowed just one run over 7.0 innings as the Mustangs posted an 11-3 victory over Messiah Thursday night at Santander Stadium in the 2015 Commonwealth Conference Baseball Championship.

With the win, Stevenson (20-17-2) posted its third 20-win season in the last four while advancing to the semifinals where the team will face top-seeded Alvernia.

Romanowski picked up his fourth win of the season, scattering five hits while striking out six.

The Mustangs opened the scoring in the top of the third on a two-out, two-run single by senior Troy Miller that scored junior Ian Eberly and freshman Jake Dimon.

The Falcons (17-19) cut their deficit in half with a run in the bottom of the fifth on a fielder's choice by Adam Janney before Stevenson blew the game open with seven runs in the top of the sixth, three of which were unearned.

The inning was highlighted by a two-run double to right center by junior Matt Myers to increase the lead to 5-1 before an RBI-double by Miller and an RBI-single by junior Nick Peifer pushed the lead to 9-1.

Stevenson added two more runs in the seventh to take its biggest lead at 11-1 on an RBI-double by junior Kevin Wu and an RBI-groundout by Eberly.

The Mustangs totaled 16 hits, their third-highest total this season, including four doubles. Eberly and Dimon had three each while Miller went 2-for-6 with three RBIs and Myers was 2-for-5 with two RBIs. Dimon finished 3-for-4 with two runs.

Ridings, who was Messiah's top pitcher this season with a 4-3 record, three complete games and a 3.41 ERA, allowed nine runs on nine hits over 5.1 innings. In two games against Stevenson this season, he surrendered 18 runs on 19 hits over 11.1 innings.

The Mustangs will take on Alvernia at 3:00 p.m., on Friday with the winner advancing to Saturday's championship series. The Crusaders defeated Widener on Thursday, 4-2.